1. Field of the Invention
The present invention relates to a toner container and a developer replenishing device to be detachably installed in an image forming apparatus in order to replenish a developing device built-in the image forming apparatus such as a copying machine, a printer, a facsimile machine, and the like with toner.
2. Description of the Related Art
A toner container disclosed in Japanese Unexamined Patent Publication (Kokai) No. 2003-280344 is known as prior art. This toner container is to be detachably installed in a developing device in order to replenish the developing device built-in an apparatus main body of an image forming apparatus with toner. More specifically, the toner container replenishes the developing device with toner when an amount of toner within the developing device becomes less than the preliminary set amount.
Such a toner container includes a box-like container to be charged with toner, a toner conveyance screw provided at a bottom of this container in order to replenish the container with toner to further replenish the developing device, an agitating member for agitating toner within the container, and a cylindrical shutter member rotationally provided at an appropriate location of the toner container along an outer peripheral surface of the toner conveyance screw. The shutter member is rotatable around the cylinder axis between a closed position where the shutter is closed and an open position where the shutter is open. The agitating member includes an agitating shaft provided in parallel with the toner conveyance screw and an agitating blade integrally rotatably mounted to the agitating shaft.
Toner within the container is conveyed to the shutter member by the toner conveyance screw while it is agitated by a rotation of the agitating blade around the agitating shaft to be replenished in the developing device through the open shutter.
In the above described toner container, a toner charging hole is provided at an appropriate position for charging toner to the container. After toner is charged into the container through this toner charging hole, a given stopper is mounted to the toner charging hole. Such a toner charging operation to the container is generally performed using a funnel-shaped charging member by manual or automatic operation. In other words, a tip of the funnel is inserted into the toner charging hole of the toner container to allow the toner flow into the funnel through a wide opening at a base end. The toner, as described above, is smoothly charged into the container from the tip of the funnel through the toner charging hole.
The toner container is attached to/detached from an apparatus main body of the image forming apparatus from a top or a side thereof. However, if a cylindrical toner charging hole is provided on a surface extending parallel to an attachment/detachment direction, it obstructs the attachment/detachment of the toner container since a projection is created when the toner charging hole is closed with a stopper. Therefore, typically, it is less likely to form a toner charging hole in a surface along the attachment/detachment direction.
In the case where the toner charging hole is formed in a top surface of the toner container, a vertical dimension of the toner container when it is provided with the stopper in the toner charging hole becomes large, and thus the apparatus main body needs more height in order to accommodate the dimension which prevents down-sizing and increases the cost of the apparatus. Consequently, the toner charging hole is not generally provided on the top surface of the toner container. In the case where a toner container extends in a longitudinal direction, further, it can be seen to be advantageous in the charging efficiency to charge toner from an end of such a long toner container.
In view of the above, the toner charging hole is always formed in an end surface of the container orthogonal to the attachment/detachment direction of the toner container. However, there is little space at the end surface of the container and the space includes therein various members for operating the shutter member, resulting in obstacles when inserting the tip of the funnel into the toner charging hole.